Water Quality by County
3,254 counties with public water systems.
| County | State | Systems | Population | Violations |
|---|---|---|---|---|
| Fairbanks North Star Borough | Alaska | 65 | 160,456 | 6,815 |
| Trumbull | Ohio | 89 | 160,312 | 6,699 |
| Butler | Pennsylvania | 182 | 159,830 | 24,329 |
| Kent | Delaware | 133 | 159,649 | 3,160 |
| Morgan | Alabama | 6 | 159,489 | 224 |
| Grayson | Texas | 50 | 159,062 | 4,304 |
| Skagit | Washington | 87 | 156,499 | 2,324 |
| Kings | California | 33 | 156,428 | 1,899 |
| Livingston Parish | Louisiana | 33 | 155,925 | 997 |
| Douglas | Kansas | 14 | 155,316 | 244 |
| Coweta | Georgia | 15 | 154,858 | 1,243 |
| Johnson | Indiana | 33 | 154,825 | 2,956 |
| Cabarrus | North Carolina | 68 | 154,756 | 13,403 |
| Shawnee | Kansas | 9 | 154,507 | 551 |
| Aiken | South Carolina | 63 | 153,654 | 1,188 |
| Hall | Georgia | 13 | 151,897 | 494 |
| Delaware | Pennsylvania | 23 | 151,505 | 3,592 |
| Winnebago | Wisconsin | 152 | 151,482 | 1,690 |
| Muskegon | Michigan | 217 | 151,467 | 2,897 |
| Wichita | Texas | 9 | 151,116 | 535 |
| Harnett | North Carolina | 9 | 151,047 | 428 |
| Calhoun | Alabama | 10 | 150,377 | 652 |
| Chittenden | Vermont | 96 | 150,283 | 8,045 |
| Jackson | Mississippi | 36 | 149,196 | 11,232 |
| Rock | Wisconsin | 156 | 148,582 | 3,788 |
| Olmsted | Minnesota | 83 | 148,383 | 573 |
| Gallatin | Montana | 207 | 147,444 | 30,683 |
| Santa Fe | New Mexico | 84 | 146,927 | 11,238 |
| Ector | Texas | 30 | 146,430 | 3,415 |
| Schenectady | New York | 35 | 146,284 | 2,911 |
| Hampshire | Massachusetts | 93 | 146,028 | 2,908 |
| Gregg | Texas | 17 | 145,987 | 1,361 |
| Grant | Washington | 268 | 145,560 | 12,635 |
| Catawba | North Carolina | 148 | 145,176 | 13,944 |
| Columbia | Georgia | 10 | 145,151 | 409 |
| Warren | Kentucky | 2 | 144,719 | 689 |
| Hawaii | Hawaii | 39 | 144,021 | 811 |
| Charles | Maryland | 171 | 143,656 | 3,860 |
| Iredell | North Carolina | 123 | 142,971 | 11,569 |
| Cambria | Pennsylvania | 70 | 141,807 | 19,662 |
| Jasper | Missouri | 40 | 141,002 | 2,855 |
| Bossier Parish | Louisiana | 27 | 140,488 | 4,038 |
| Pennington | South Dakota | 157 | 140,305 | 11,864 |
| Cache | Utah | 45 | 139,014 | 9,272 |
| Bonneville | Idaho | 135 | 138,969 | 4,633 |
| Cullman | Alabama | 11 | 138,799 | 398 |
| Missoula | Montana | 243 | 138,758 | 31,553 |
| Elkhart | Indiana | 282 | 138,184 | 26,344 |
| Washington | Tennessee | 2 | 138,126 | 129 |
| Jackson | Michigan | 230 | 137,611 | 3,320 |
| Comanche | Oklahoma | 25 | 137,288 | 5,160 |
| Kenosha | Wisconsin | 227 | 137,280 | 15,435 |
| Hardin | Kentucky | 4 | 136,859 | 885 |
| Franklin | Pennsylvania | 122 | 136,296 | 18,681 |
| Monroe | Michigan | 82 | 136,030 | 1,845 |
| Rensselaer | New York | 147 | 135,298 | 3,867 |
| Sandoval | New Mexico | 62 | 135,220 | 12,440 |
| Livingston | Michigan | 431 | 135,167 | 6,236 |
| Alamance | North Carolina | 99 | 134,389 | 11,703 |
| Humboldt | California | 91 | 134,283 | 2,001 |
| Penuelas Municipio | Puerto Rico | 12 | 133,990 | 7,659 |
| Marshall | Alabama | 9 | 133,944 | 437 |
| Rowan | North Carolina | 195 | 133,720 | 16,867 |
| Pickens | South Carolina | 46 | 133,635 | 545 |
| Berkshire | Massachusetts | 179 | 133,575 | 4,895 |
| Scott | Minnesota | 115 | 133,319 | 1,081 |
| Berrien | Michigan | 210 | 133,064 | 4,797 |
| Henderson | Texas | 76 | 132,983 | 5,468 |
| Flagler | Florida | 25 | 132,797 | 1,068 |
| Hunt | Texas | 30 | 132,675 | 3,291 |
| Schuylkill | Pennsylvania | 188 | 132,673 | 19,535 |
| Carroll | Maryland | 224 | 132,585 | 3,560 |
| Franklin | Washington | 79 | 132,513 | 3,941 |
| Ulster | New York | 445 | 132,066 | 40,480 |
| St. Clair | Michigan | 104 | 131,964 | 2,483 |
| Tangipahoa Parish | Louisiana | 35 | 131,935 | 1,445 |
| Washington | Wisconsin | 268 | 131,895 | 7,862 |
| Tazewell | Illinois | 100 | 131,500 | 7,258 |
| Bastrop | Texas | 21 | 130,729 | 1,749 |
| Bibb | Georgia | 4 | 130,597 | 177 |
| Wright | Minnesota | 129 | 130,391 | 1,276 |
| Madison | Mississippi | 17 | 129,931 | 7,946 |
| Cochise | Arizona | 104 | 129,689 | 19,234 |
| Jefferson | New York | 154 | 129,617 | 2,971 |
| Licking | Ohio | 88 | 129,554 | 6,135 |
| Terrebonne Parish | Louisiana | 2 | 128,118 | 50 |
| Sebastian | Arkansas | 21 | 127,973 | 1,403 |
| Sullivan | New York | 494 | 127,945 | 23,388 |
| Houston | Alabama | 16 | 127,626 | 1,072 |
| Portage | Ohio | 173 | 127,607 | 9,333 |
| Clarke | Georgia | 11 | 127,468 | 883 |
| Stafford | Virginia | 18 | 127,351 | 1,020 |
| Washington | Maryland | 89 | 127,174 | 1,539 |
| Chautauqua | New York | 192 | 126,746 | 9,066 |
| Monroe | Indiana | 11 | 126,334 | 676 |
| Craven | North Carolina | 15 | 125,817 | 902 |
| St. Mary's | Maryland | 200 | 125,614 | 2,495 |
| Linn | Oregon | 167 | 125,361 | 9,206 |
| Clay | Missouri | 21 | 125,248 | 851 |
| Lauderdale | Alabama | 8 | 125,019 | 164 |